2,423 research outputs found

    The diagnosis of mental disorders: the problem of reification

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    A pressing need for interrater reliability in the diagnosis of mental disorders emerged during the mid-twentieth century, prompted in part by the development of diverse new treatments. The Diagnostic and Statistical Manual of Mental Disorders (DSM), third edition answered this need by introducing operationalized diagnostic criteria that were field-tested for interrater reliability. Unfortunately, the focus on reliability came at a time when the scientific understanding of mental disorders was embryonic and could not yield valid disease definitions. Based on accreting problems with the current DSM-fourth edition (DSM-IV) classification, it is apparent that validity will not be achieved simply by refining criteria for existing disorders or by the addition of new disorders. Yet DSM-IV diagnostic criteria dominate thinking about mental disorders in clinical practice, research, treatment development, and law. As a result, the modernDSMsystem, intended to create a shared language, also creates epistemic blinders that impede progress toward valid diagnoses. Insights that are beginning to emerge from psychology, neuroscience, and genetics suggest possible strategies for moving forward

    Photosynthesis dependent acidification of perialgal vacuoles in theParamedum bursaria/Chlorella symbiosis. Visualization by monensin

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    After treatment with the carboxylic ionophore monensin theChlorella containing perialgal vacuoles of the greenParamecium bursaria swell. TheParamecium cells remain motile at this concentration for at least one day. The swelling is only observed in illuminated cells and can be inhibited by DCMU. We assume that during photosynthesis the perialgal vacuoles are acidified and that monensin exchanges H+ ions against monovalent cations (here K+). In consequence the osmotic value of the vacuoles increases. The proton gradient is believed to drive the transport of maltose from the symbiont into the host. Another but light independent effect of the monensin treatment is the swelling of peripheral alveoles of the ciliates, likewise indicating that the alveolar membrane contains an active proton pump

    Collapse of superconductivity in a hybrid tin-graphene Josephson junction array

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    When a Josephson junction array is built with hybrid superconductor/metal/superconductor junctions, a quantum phase transition from a superconducting to a two-dimensional (2D) metallic ground state is predicted to happen upon increasing the junction normal state resistance. Owing to its surface-exposed 2D electron gas and its gate-tunable charge carrier density, graphene coupled to superconductors is the ideal platform to study the above-mentioned transition between ground states. Here we show that decorating graphene with a sparse and regular array of superconducting nanodisks enables to continuously gate-tune the quantum superconductor-to-metal transition of the Josephson junction array into a zero-temperature metallic state. The suppression of proximity-induced superconductivity is a direct consequence of the emergence of quantum fluctuations of the superconducting phase of the disks. Under perpendicular magnetic field, the competition between quantum fluctuations and disorder is responsible for the resilience at the lowest temperatures of a superconducting glassy state that persists above the upper critical field. Our results provide the entire phase diagram of the disorder and magnetic field-tuned transition and unveil the fundamental impact of quantum phase fluctuations in 2D superconducting systems.Comment: 25 pages, 6 figure

    Simulation studies of age-specific lifetime major depression prevalence

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    BACKGROUND: The lifetime prevalence (LTP) of Major Depressive Disorder (MDD) is the proportion of a population having met criteria for MDD during their life up to the time of assessment. Expectation holds that LTP should increase with age, but this has not usually been observed. Instead, LTP typically increases in the teenage years and twenties, stabilizes in adulthood and then begins to decline in middle age. Proposed explanations for this pattern include: a cohort effect (increasing incidence in more recent birth cohorts), recall failure and/or differential mortality. Declining age-specific incidence may also play a role. METHODS: We used a simulation model to explore patterns of incidence, recall and mortality in relation to the observed pattern of LTP. Lifetime prevalence estimates from the 2002 Canadian Community Health Survey, Mental Health and Wellbeing (CCHS 1.2) were used for model validation and calibration. RESULTS: Incidence rates predicting realistic values for LTP in the 15-24 year age group (where mortality is unlikely to substantially influence prevalence) lead to excessive LTP later in life, given reasonable assumptions about mortality and recall failure. This suggests that (in the absence of cohort effects) incidence rates decline with age. Differential mortality may make a contribution to the prevalence pattern, but only in older age categories. Cohort effects can explain the observed pattern, but only if recent birth cohorts have a much higher (approximately 10-fold greater) risk and if incidence has increased with successive birth cohorts over the past 60-70 years. CONCLUSIONS: The pattern of lifetime prevalence observed in cross-sectional epidemiologic studies seems most plausibly explained by incidence that declines with age and where some respondents fail to recall past episodes. A cohort effect is not a necessary interpretation of the observed pattern of age-specific lifetime prevalence

    Successful new product development by optimizing development process effectiveness in highly regulated sectors: the case of the Spanish medical devices sector

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    Rapid development and commercialization of new products is of vital importance for small and medium sized enterprises (SME) in regulated sectors. Due to strict regulations, competitive advantage can hardly be achieved through the effectiveness of product concepts only. If an SME in a highly regulated sector wants to excell in new product development (NPD) performance, the company should focus on the flexibility, speed, and productivity of its NPD function: i.e. the development process effectiveness. Our main research goals are first to explore if SMEs should focus on their their development process effectiveness rather than on their product concept effectiveness to achieve high NPD performance; and second, to explore whether a shared pattern in the organization of the NPD function can be recognized to affect NPD performance positively. The medical devices sector in Spain is used as an example of a\ud highly regulated sector. A structured survey among 11 SMEs, of which 2 were studied also as in in-depth case studies, led to the following results. First of all, indeed the companies in the dataset which focused on the effectiveness of their development process, stood out in NPD performance. Further, the higher performing companies did have a number of commonalities in the organisation of their NPD function: 1) The majority of the higher performing firms had an NPD strategy characterized by a predominantly incremental project portfolio.\ud 2) a) Successful firms with an incremental project portfolio combined this with a functional team structure b) Successful firms with a radical project portfolio combined this with a heavyweight or autonomous team structure.\ud 3) A negative reciprocal relationship exists between formalization of the NPD processes and the climate of the NPD function, in that a formalized NPD process and an innovative climate do not seem to reinforce each other. Innovative climate combined with an informal NPD process does however contribute positively to NPD performance. This effect was stronger in combination with a radical project portfolio. The highest NPD performance was measured for companies focusing mainly on incremental innovation. It is argued that in highly regulated sectors, companies with an incremental product portfolio would benefit from employing a functional structure. Those companies who choose for a more radical project portfolio in highly regulated sectors should be aware\ud that they are likely to excell only in the longer term by focusing on strategic flexibility. In their NPD organization, they might be well advised to combine informal innovation processes with an innovative climate

    Spinal involvement in mucopolysaccharidosis IVA (Morquio-Brailsford or Morquio A syndrome): presentation, diagnosis and management.

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    Mucopolysaccharidosis IVA (MPS IVA), also known as Morquio-Brailsford or Morquio A syndrome, is a lysosomal storage disorder caused by a deficiency of the enzyme N-acetyl-galactosamine-6-sulphate sulphatase (GALNS). MPS IVA is multisystemic but manifests primarily as a progressive skeletal dysplasia. Spinal involvement is a major cause of morbidity and mortality in MPS IVA. Early diagnosis and timely treatment of problems involving the spine are critical in preventing or arresting neurological deterioration and loss of function. This review details the spinal manifestations of MPS IVA and describes the tools used to diagnose and monitor spinal involvement. The relative utility of radiography, computed tomography (CT) and magnetic resonance imaging (MRI) for the evaluation of cervical spine instability, stenosis, and cord compression is discussed. Surgical interventions, anaesthetic considerations, and the use of neurophysiological monitoring during procedures performed under general anaesthesia are reviewed. Recommendations for regular radiological imaging and neurologic assessments are presented, and the need for a more standardized approach for evaluating and managing spinal involvement in MPS IVA is addressed

    Mental disorders in a population sample with musculoskeletal disorders

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    BACKGROUND: Studies using clinical and volunteer samples have reported an elevated prevalence of mood disorders in association with rheumatoid arthritis and osteoarthritis. Clinical studies using anxiety rating scales have reported inconsistent results, but studies using diagnostic instruments have reported that anxiety disorders may be even more strongly associated with arthritis than is depression. One study reported an association between lifetime substance use disorders and arthritis. METHODS: Data from iteration 1.2 of the Canadian Community Health Survey (CCHS) were used. This was a large-scale national Canadian health survey which administered the World Mental Health Composite International Diagnostic Interview to a sample of 36,984 subjects randomly selected from the national population. In the CCHS 1.2, subjects were asked whether they had been diagnosed by a health professional with arthritis or rheumatism. RESULTS: Subjects reporting arthritis or rheumatism had an elevated prevalence of mood, anxiety and substance use disorders. The strength of association resembled that seen in an omnibus category reporting any chronic condition, but was weaker than that seen with back pain or fibromyalgia. The effect of arthritis or rheumatism interacted with age, such that the odds ratios became smaller with increasing age. Mood and anxiety disorders, along with arthritis or rheumatism made an independent contribution to disability. CONCLUSION: Arthritis is associated with psychiatric morbidity in the general population, and this morbidity is seen across a variety of mental disorders. The strength of association is consistent with that seen in persons with other self-reported medical conditions

    SWS observations of IR emission features towards compact HII regions

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    We present ISO Short Wavelength Spectrometer (SWS) grating spectra of six compact HII regions. In addition to strong emission lines from atomic species these spectra display infrared bands attributed to Polycyclic Aromatic Hydrocarbons (PAHs). The continuous spectral coverage of the present observations and the high spectral resolution allow to describe the detailed structure of the emission bands: the 7.7μm band is composed of two bands at 7.6 and 7.8μm, the 6.2 μm band has a long wavelength extension, there is a plateau of emission between 6 and 7μm and a new feature is reported at 11.0μm in addition to the well-known 11.2μm band. These observations also reveal large variations in the relative intensities of the dust bands, in particular between the 7.7 and 8.6μm bands. In one extreme case, the 8.6μm band is stronger than the 7.7μm band. These observations are compared to a mixed population of ionized PAHs, using new laboratory measurements
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